cycx_x25.c

linux-2.6.15.6

static int cycx_netdevice_stop(struct net_device *dev)
{
	struct cycx_x25_channel *chan = dev->priv;

	netif_stop_queue(dev);

	if (chan->state == WAN_CONNECTED || chan->state == WAN_CONNECTING)
		cycx_x25_chan_disconnect(dev);

	return 0;
}

/* Build media header.
 * o encapsulate packet according to encapsulation type.
 *
 * The trick here is to put packet type (Ethertype) into 'protocol' field of
 * the socket buffer, so that we don't forget it.  If encapsulation fails,
 * set skb->protocol to 0 and discard packet later.
 *
 * Return:	media header length. */
static int cycx_netdevice_hard_header(struct sk_buff *skb,
				      struct net_device *dev, u16 type,
				      void *daddr, void *saddr, unsigned len)
{
	skb->protocol = type;

	return dev->hard_header_len;
}

/* * Re-build media header.
 * Return:	1	physical address resolved.
 *		0	physical address not resolved */
static int cycx_netdevice_rebuild_header(struct sk_buff *skb)
{
	return 1;
}

/* Send a packet on a network interface.
 * o set busy flag (marks start of the transmission).
 * o check link state. If link is not up, then drop the packet.
 * o check channel status. If it's down then initiate a call.
 * o pass a packet to corresponding WAN device.
 * o free socket buffer
 *
 * Return:	0	complete (socket buffer must be freed)
 *		non-0	packet may be re-transmitted (tbusy must be set)
 *
 * Notes:
 * 1. This routine is called either by the protocol stack or by the "net
 *    bottom half" (with interrupts enabled).
 * 2. Setting tbusy flag will inhibit further transmit requests from the
 *    protocol stack and can be used for flow control with protocol layer. */
static int cycx_netdevice_hard_start_xmit(struct sk_buff *skb,
					  struct net_device *dev)
{
	struct cycx_x25_channel *chan = dev->priv;
	struct cycx_device *card = chan->card;

	if (!chan->svc)
		chan->protocol = skb->protocol;

	if (card->wandev.state != WAN_CONNECTED)
		++chan->ifstats.tx_dropped;
	else if (chan->svc && chan->protocol &&
		 chan->protocol != skb->protocol) {
		printk(KERN_INFO
		       "%s: unsupported Ethertype 0x%04X on interface %s!\n",
		       card->devname, skb->protocol, dev->name);
		++chan->ifstats.tx_errors;
	} else if (chan->protocol == ETH_P_IP) {
		switch (chan->state) {
		case WAN_DISCONNECTED:
			if (cycx_x25_chan_connect(dev)) {
				netif_stop_queue(dev);
				return -EBUSY;
			}
			/* fall thru */
		case WAN_CONNECTED:
			reset_timer(dev);
			dev->trans_start = jiffies;
			netif_stop_queue(dev);

			if (cycx_x25_chan_send(dev, skb))
				return -EBUSY;

			break;
		default:
			++chan->ifstats.tx_dropped;
			++card->wandev.stats.tx_dropped;
	}
	} else { /* chan->protocol == ETH_P_X25 */
		switch (skb->data[0]) {
		case 0: break;
		case 1: /* Connect request */
			cycx_x25_chan_connect(dev);
			goto free_packet;
		case 2: /* Disconnect request */
			cycx_x25_chan_disconnect(dev);
			goto free_packet;
	        default:
			printk(KERN_INFO
			       "%s: unknown %d x25-iface request on %s!\n",
			       card->devname, skb->data[0], dev->name);
			++chan->ifstats.tx_errors;
			goto free_packet;
		}

		skb_pull(skb, 1); /* Remove control byte */
		reset_timer(dev);
		dev->trans_start = jiffies;
		netif_stop_queue(dev);

		if (cycx_x25_chan_send(dev, skb)) {
			/* prepare for future retransmissions */
			skb_push(skb, 1);
			return -EBUSY;
		}
	}

free_packet:
	dev_kfree_skb(skb);

	return 0;
}

/* Get Ethernet-style interface statistics.
 * Return a pointer to struct net_device_stats */
static struct net_device_stats *cycx_netdevice_get_stats(struct net_device *dev)
{
	struct cycx_x25_channel *chan = dev->priv;

	return chan ? &chan->ifstats : NULL;
}

/* Interrupt Handlers */
/* X.25 Interrupt Service Routine. */
static void cycx_x25_irq_handler(struct cycx_device *card)
{
	struct cycx_x25_cmd cmd;
	u16 z = 0;

	card->in_isr = 1;
	card->buff_int_mode_unbusy = 0;
	cycx_peek(&card->hw, X25_RXMBOX_OFFS, &cmd, sizeof(cmd));

	switch (cmd.command) {
	case X25_DATA_INDICATION:
		cycx_x25_irq_rx(card, &cmd);
		break;
	case X25_ACK_FROM_VC:
		cycx_x25_irq_tx(card, &cmd);
		break;
	case X25_LOG:
		cycx_x25_irq_log(card, &cmd);
		break;
	case X25_STATISTIC:
		cycx_x25_irq_stat(card, &cmd);
		break;
	case X25_CONNECT_CONFIRM:
		cycx_x25_irq_connect_confirm(card, &cmd);
		break;
	case X25_CONNECT_INDICATION:
		cycx_x25_irq_connect(card, &cmd);
		break;
	case X25_DISCONNECT_INDICATION:
		cycx_x25_irq_disconnect(card, &cmd);
		break;
	case X25_DISCONNECT_CONFIRM:
		cycx_x25_irq_disconnect_confirm(card, &cmd);
		break;
	case X25_LINE_ON:
		cycx_set_state(card, WAN_CONNECTED);
		break;
	case X25_LINE_OFF:
		cycx_set_state(card, WAN_DISCONNECTED);
		break;
	default:
		cycx_x25_irq_spurious(card, &cmd);
		break;
	}

	cycx_poke(&card->hw, 0, &z, sizeof(z));
	cycx_poke(&card->hw, X25_RXMBOX_OFFS, &z, sizeof(z));
	card->in_isr = 0;
}

/* Transmit interrupt handler.
 *	o Release socket buffer
 *	o Clear 'tbusy' flag */
static void cycx_x25_irq_tx(struct cycx_device *card, struct cycx_x25_cmd *cmd)
{
	struct net_device *dev;
	struct wan_device *wandev = &card->wandev;
	u8 lcn;

	cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));

	/* unbusy device and then dev_tint(); */
	dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
	if (dev) {
		card->buff_int_mode_unbusy = 1;
		netif_wake_queue(dev);
	} else
		printk(KERN_ERR "%s:ackvc for inexistent lcn %d\n",
				 card->devname, lcn);
}

/* Receive interrupt handler.
 * This routine handles fragmented IP packets using M-bit according to the
 * RFC1356.
 * o map logical channel number to network interface.
 * o allocate socket buffer or append received packet to the existing one.
 * o if M-bit is reset (i.e. it's the last packet in a sequence) then
 *   decapsulate packet and pass socket buffer to the protocol stack.
 *
 * Notes:
 * 1. When allocating a socket buffer, if M-bit is set then more data is
 *    coming and we have to allocate buffer for the maximum IP packet size
 *    expected on this channel.
 * 2. If something goes wrong and X.25 packet has to be dropped (e.g. no
 *    socket buffers available) the whole packet sequence must be discarded. */
static void cycx_x25_irq_rx(struct cycx_device *card, struct cycx_x25_cmd *cmd)
{
	struct wan_device *wandev = &card->wandev;
	struct net_device *dev;
	struct cycx_x25_channel *chan;
	struct sk_buff *skb;
	u8 bitm, lcn;
	int pktlen = cmd->len - 5;

	cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
	cycx_peek(&card->hw, cmd->buf + 4, &bitm, sizeof(bitm));
	bitm &= 0x10;

	dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
	if (!dev) {
		/* Invalid channel, discard packet */
		printk(KERN_INFO "%s: receiving on orphaned LCN %d!\n",
				 card->devname, lcn);
		return;
	}

	chan = dev->priv;
	reset_timer(dev);

	if (chan->drop_sequence) {
		if (!bitm)
			chan->drop_sequence = 0;
		else
			return;
	}

	if ((skb = chan->rx_skb) == NULL) {
		/* Allocate new socket buffer */
		int bufsize = bitm ? dev->mtu : pktlen;

		if ((skb = dev_alloc_skb((chan->protocol == ETH_P_X25 ? 1 : 0) +
					 bufsize +
					 dev->hard_header_len)) == NULL) {
			printk(KERN_INFO "%s: no socket buffers available!\n",
					 card->devname);
			chan->drop_sequence = 1;
			++chan->ifstats.rx_dropped;
			return;
		}

		if (chan->protocol == ETH_P_X25) /* X.25 socket layer control */
			/* 0 = data packet (dev_alloc_skb zeroed skb->data) */
			skb_put(skb, 1);

		skb->dev = dev;
		skb->protocol = htons(chan->protocol);
		chan->rx_skb = skb;
	}

	if (skb_tailroom(skb) < pktlen) {
		/* No room for the packet. Call off the whole thing! */
		dev_kfree_skb_irq(skb);
		chan->rx_skb = NULL;

		if (bitm)
			chan->drop_sequence = 1;

		printk(KERN_INFO "%s: unexpectedly long packet sequence "
			"on interface %s!\n", card->devname, dev->name);
		++chan->ifstats.rx_length_errors;
		return;
	}

	/* Append packet to the socket buffer  */
	cycx_peek(&card->hw, cmd->buf + 5, skb_put(skb, pktlen), pktlen);

	if (bitm)
		return; /* more data is coming */

	chan->rx_skb = NULL;		/* dequeue packet */

	++chan->ifstats.rx_packets;
	chan->ifstats.rx_bytes += pktlen;

	skb->mac.raw = skb->data;
	netif_rx(skb);
	dev->last_rx = jiffies;		/* timestamp */
}

/* Connect interrupt handler. */
static void cycx_x25_irq_connect(struct cycx_device *card,
				 struct cycx_x25_cmd *cmd)
{
	struct wan_device *wandev = &card->wandev;
	struct net_device *dev = NULL;
	struct cycx_x25_channel *chan;
	u8 d[32],
	   loc[24],
	   rem[24];
	u8 lcn, sizeloc, sizerem;

	cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
	cycx_peek(&card->hw, cmd->buf + 5, &sizeloc, sizeof(sizeloc));
	cycx_peek(&card->hw, cmd->buf + 6, d, cmd->len - 6);

	sizerem = sizeloc >> 4;
	sizeloc &= 0x0F;

	loc[0] = rem[0] = '\0';

	if (sizeloc)
		nibble_to_byte(d, loc, sizeloc, 0);

	if (sizerem)
		nibble_to_byte(d + (sizeloc >> 1), rem, sizerem, sizeloc & 1);

	dprintk(1, KERN_INFO "%s:lcn=%d, local=%s, remote=%s\n",
			  __FUNCTION__, lcn, loc, rem);

	dev = cycx_x25_get_dev_by_dte_addr(wandev, rem);
	if (!dev) {
		/* Invalid channel, discard packet */
		printk(KERN_INFO "%s: connect not expected: remote %s!\n",
				 card->devname, rem);
		return;
	}

	chan = dev->priv;
	chan->lcn = lcn;
	cycx_x25_connect_response(card, chan);
	cycx_x25_set_chan_state(dev, WAN_CONNECTED);
}

/* Connect confirm interrupt handler. */
static void cycx_x25_irq_connect_confirm(struct cycx_device *card,
					 struct cycx_x25_cmd *cmd)
{
	struct wan_device *wandev = &card->wandev;
	struct net_device *dev;
	struct cycx_x25_channel *chan;
	u8 lcn, key;

	cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
	cycx_peek(&card->hw, cmd->buf + 1, &key, sizeof(key));
	dprintk(1, KERN_INFO "%s: %s:lcn=%d, key=%d\n",
			  card->devname, __FUNCTION__, lcn, key);

	dev = cycx_x25_get_dev_by_lcn(wandev, -key);
	if (!dev) {
		/* Invalid channel, discard packet */
		clear_bit(--key, (void*)&card->u.x.connection_keys);
		printk(KERN_INFO "%s: connect confirm not expected: lcn %d, "
				 "key=%d!\n", card->devname, lcn, key);
		return;
	}

	clear_bit(--key, (void*)&card->u.x.connection_keys);
	chan = dev->priv;
	chan->lcn = lcn;
	cycx_x25_set_chan_state(dev, WAN_CONNECTED);
}

/* Disconnect confirm interrupt handler. */
static void cycx_x25_irq_disconnect_confirm(struct cycx_device *card,
					    struct cycx_x25_cmd *cmd)
{
	struct wan_device *wandev = &card->wandev;
	struct net_device *dev;
	u8 lcn;

	cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
	dprintk(1, KERN_INFO "%s: %s:lcn=%d\n",
			  card->devname, __FUNCTION__, lcn);
	dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
	if (!dev) {
		/* Invalid channel, discard packet */
		printk(KERN_INFO "%s:disconnect confirm not expected!:lcn %d\n",
				 card->devname, lcn);
		return;
	}

	cycx_x25_set_chan_state(dev, WAN_DISCONNECTED);
}

/* disconnect interrupt handler. */
static void cycx_x25_irq_disconnect(struct cycx_device *card,
				    struct cycx_x25_cmd *cmd)
{
	struct wan_device *wandev = &card->wandev;
	struct net_device *dev;
	u8 lcn;

	cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
	dprintk(1, KERN_INFO "%s:lcn=%d\n", __FUNCTION__, lcn);

	dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
	if (dev) {
		struct cycx_x25_channel *chan = dev->priv;

		cycx_x25_disconnect_response(card, chan->link, lcn);
		cycx_x25_set_chan_state(dev, WAN_DISCONNECTED);
	} else
		cycx_x25_disconnect_response(card, 0, lcn);
}

/* LOG interrupt handler. */
static void cycx_x25_irq_log(struct cycx_device *card, struct cycx_x25_cmd *cmd)
{
#if CYCLOMX_X25_DEBUG
	char bf[20];
	u16 size, toread, link, msg_code;
	u8 code, routine;

	cycx_peek(&card->hw, cmd->buf, &msg_code, sizeof(msg_code));
	cycx_peek(&card->hw, cmd->buf + 2, &link, sizeof(link));
	cycx_peek(&card->hw, cmd->buf + 4, &size, sizeof(size));
	/* at most 20 bytes are available... thanks to Daniela :) */
	toread = size < 20 ? size : 20;
	cycx_peek(&card->hw, cmd->buf + 10, &bf, toread);
	cycx_peek(&card->hw, cmd->buf + 10 + toread, &code, 1);
	cycx_peek(&card->hw, cmd->buf + 10 + toread + 1, &routine, 1);

	printk(KERN_INFO "cycx_x25_irq_handler: X25_LOG (0x4500) indic.:\n");
	printk(KERN_INFO "cmd->buf=0x%X\n", cmd->buf);
	printk(KERN_INFO "Log message code=0x%X\n", msg_code);
	printk(KERN_INFO "Link=%d\n", link);
	printk(KERN_INFO "log code=0x%X\n", code);
	printk(KERN_INFO "log routine=0x%X\n", routine);
	printk(KERN_INFO "Message size=%d\n", size);
	hex_dump("Message", bf, toread);
#endif
}

/* STATISTIC interrupt handler. */
static void cycx_x25_irq_stat(struct cycx_device *card,
			      struct cycx_x25_cmd *cmd)
{
	cycx_peek(&card->hw, cmd->buf, &card->u.x.stats,
		  sizeof(card->u.x.stats));
	hex_dump("cycx_x25_irq_stat", (unsigned char*)&card->u.x.stats,
		 sizeof(card->u.x.stats));
	cycx_x25_dump_stats(&card->u.x.stats);
	wake_up_interruptible(&card->wait_stats);
}

/* Spurious interrupt handler.
 * o print a warning
 * If number of spurious interrupts exceeded some limit, then ??? */
static void cycx_x25_irq_spurious(struct cycx_device *card,
				  struct cycx_x25_cmd *cmd)
{
	printk(KERN_INFO "%s: spurious interrupt (0x%X)!\n",
			 card->devname, cmd->command);
}
#ifdef CYCLOMX_X25_DEBUG
static void hex_dump(char *msg, unsigned char *p, int len)
{
	unsigned char hex[1024],
	    	* phex = hex;

	if (len >= (sizeof(hex) / 2))
		len = (sizeof(hex) / 2) - 1;

	while (len--) {
		sprintf(phex, "%02x", *p++);
		phex += 2;
	}

	printk(KERN_INFO "%s: %s\n", msg, hex);
}
#endif

/* Cyclom 2X Firmware-Specific Functions */
/* Exec X.25 command. */
static int x25_exec(struct cycx_device *card, int command, int link,
		    void *d1, int len1, void *d2, int len2)
{
	struct cycx_x25_cmd c;
	unsigned long flags;
	u32 addr = 0x1200 + 0x2E0 * link + 0x1E2;
	u8 retry = CYCX_X25_MAX_CMD_RETRY;
	int err = 0;

	c.command = command;
	c.link = link;
	c.len = len1 + len2;

	spin_lock_irqsave(&card->u.x.lock, flags);

	/* write command */
	cycx_poke(&card->hw, X25_MBOX_OFFS, &c, sizeof(c) - sizeof(c.buf));

	/* write X.25 data */
	if (d1) {
		cycx_poke(&card->hw, addr, d1, len1);

		if (d2) {
			if (len2 > 254) {
				u32 addr1 = 0xA00 + 0x400 * link;

				cycx_poke(&card->hw, addr + len1, d2, 249);
				cycx_poke(&card->hw, addr1, ((u8*)d2) + 249,
					  len2 - 249);
			} else
				cycx_poke(&card->hw, addr + len1, d2, len2);
		}
	}

	/* generate interruption, executing command */
	cycx_intr(&card->hw);

	/* wait till card->mbox == 0 */
	do {
		err = cycx_exec(card->mbox);
	} while (retry-- && err);

	spin_unlock_irqrestore(&card->u.x.lock, flags);

	return err;
}